Feature Name: Auto Note Select on Playback

Description:
This PR introduces a feature to automatically select the note currently being played by the playback cursor.
This behavior emulates the note selection mode during UTAU Mode2 playback, allowing users to monitor and adjust note properties in real-time during auditioning.

Key Changes:

1. Core Logic: Implemented note hit-testing and selection logic in NotesViewModel.cs triggered by playback position updates.
2. Configuration Switch: Added the NoteSelectionOnPlay preference setting (default: disabled) to Preferences.cs and bound it in PreferencesViewModel.cs.
3. User Interface: Added a toggle switch for this feature to the "Playback" tab of the Preferences dialog (PreferencesDialog.axaml).

How to Test:

1. Go to Preferences, enable the "Auto Note Select on Playback" option.
2. Play any project and observe that the notes being passed by the playback cursor are automatically selected.